High traction sole and heel



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Sept. 24, 1946. H. AQ'HUSTED Y HIGH TRACTION SOLE AND HEEL Filed A'pril- 28, 1945 Patented Sept. 2 4, 1946 UNITED orrics "2;,;l08,21l

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1945, Serial No. 599,308

Application 28,

It is an objectof this invention toprovide a sole and heel each of which has a tread surface particularly adapting it to use in snow covered hill country.

The above and other object willbe made clear precisely similar to .the pyramidsin the a rea 1,5,

in the following detailed description taken in connection with the annexed drawing, in which:

Figure l is a plan view of the improved sole and heel; r

Fig. 2 is a section on the line 2-2 of Fig. 1; Fig. 3 is a section on the line 3-3 of Fig. 1. There is a sharpdistinction in of a tread-for vehicle tires and in of a tread for a shoe.

ing a'wide variety of conditions and to exerting strong tractive force in a single direction in the plane of the contact of the tire with the ground. A shoe "sole representing a relatively small investment may be specialized to meet any particular service. A vehicle tire operates at high rotary speeds and under severe vibration. It is not, therefore, necessary to payany particular attention to the ability ofa vehicle tire to free itself from clogging the tread with snow or mud. In a shoe sole, the element of centrifugal force is entirely lacking and the element of vibration is practically nil. As a result, it is necessary in designing a shoe tread for use in snow or mud to arrange the elements of the tread so as to minimize clogging of the tread by such snow or mud. It is also necessary to take into account the mechanics of human walking. The weight of the body is never equally distributed over the entire area of the sole in contact with the ground, but rather concentration of weight shifts from point to point throughout the sole, depending on the nature of the terrain being covered. In designing a shoe tread, the tread elements must be constructed and distributed to meet these exigencies.

In Fig. 1 there is shown a sole iii to which is attached a heel I2. Adjacent the toe is a raised area [4, the surface of which is diagonally grooved at [6 to form a plurality of pyramids having rhomboidal bases. The spacing of these pyramids is preferably about s inch peak to peak, while the height of the pyramids, base'to peak, approximates 3% of an inch. The area i6 terminates inwardly from the toe in a zig-zag line H.

Spaced from the zig-zag line H, but following its pattern, i a zig-zag r'b l8 followed by similar ribs i8 liberally spaced by substantially the same distance as the first rib i8 is spaced from the line I1. Each of these ribs I8 is surfaced with a plurality of rhomboidal pyramids which are the requirements the requirements Generally speaking, a ve- .hicle tire must be designed with a view to meet sheet; of cork is provided scrib'edin detail in co-pending application, Serial ed any suitable desired, it is necessary to but which are approximately onerhalf the size of the pyramids .in area L ac pi he ilQ approximately 1% inch wide.

A the sole narrows toward the instep, the overall length of the ribs l8 decreases, and spaced rearwardly from the last of the ribs there is provided a series of transverse which are semi-cylindrical in cross section, and respectively decrease in diameter toward the instep.

As best seen in Fig. 2, the top side of the sole is recessed to receive a sheet of cork 30. This for the purposes de- No. 590,803, filed of even date herewith.

The heel i2 has at its inner or breast margin a relatively plain space 32 on which may be moldindicia, such as a trade-mark, the Adjacent the plain area 32 is a heel size, etc.

which is identical knurled area 34, the surface of with that of the toe area Hi. Adjacent the end of the knurled area 34, and from there to the rear of the heel, there are molded a series of ribs 36 which are semi-cylindrical in cross section, and are separated by grooves 38. I 1

In ordinary walking, the rear end of the heel strikes the glOundlI'St, subsequently the entire heel isin contact with the ground before the sole makes contact with the ground. This is particularly true in walking down grade. On a severe up grade, however, the toe touches the ground first, and the heel may not be involved at all. Since normally the heel takes the most severe impact, it is at the heel where ice or snow has the greatest tendency to form a ball and thus to clog the tread. Accordingly, while friction is distinctly minimize the opportunities for anchorage of snow or ice, and thereby to minimize the tendency toward balling. It will be noted that the surface of the heel l2 responds to this principle in that no really deep anchorage is provided. At the extreme toe of the sole, the pressure involved is usually not so great as at the heel, but probably less flexure takes place within the area l4 than at any other part of the sole. Accordingly, there is less tendency for this area to be self clearing, and for this reason an area of minimum anchorage is provided at the toe.

The area occupied by the relatively coarse ribs i8 is the area where maximum flexure occurs, and is also the area which carries most of the tractive effect in walking. Accordingly, the ribs l8 are designed to give a solid bite into snow or mud, and although this design affords excellent anribs 22, 24 and 26,

3 chorage which might result in balling, such anchorage is provided in what is substantially a self-clearing area.

The soles and heels are preferably molded of synthetic rubber, since the intrinsic characteristics of such rubber may be accurately controlled. The invention is not, however, limited to any particular formula, nor indeed to synthetic rubber. Various dimensions have been indicated and as a practical matter these are preferred. They are given, however, by way of illustration and not of limitation.

I claim:

1. A sole, a heel attached thereto, said sole and heel being molded of rubber-like material, a tread on said sole and heel, said tread comprising: an area at the toe knurled to provide traction in any direction in the plane of the sole and to provide minimum anchorage normal to said plane; an area at the rear of said heel providing traction in the plane of said heel primarily in the direction of the toe, the remainder of said heel surface substantially duplicating said toe area; and an area in said sole intermediate said toe area and the shank comprising zig-zag ribs of substantial width and substantially spaced, one from the other, said tread being formed of the material of said sole and heel.

2. A sole, a heel attached thereto, said sole and heel being molded of rubber-like material, a tread on said sole and heel, said tread comprising: an area at the toe knurled to provide traction in any direction in the plane of the sole and to provide minimum anchorage nonnal to said plane; an area at the rear of said heel providing traction in the plane of said heel primarily in the direction of the toe,'the remainder of said heel surface substantially duplicating said toe area; and an rea in said sole intermediate said toe area and the shank comprisingzig-zag ribs of substantial w dth and substantially spaced, one from the other, aid tread being formed of the material of said sole and heel, the free surface of said zig-zag rib being knurled to a smaller pattern than said toe area.

HARRY A. HUSTED. 

